Gellan Gum

Overview

Gellan gum is a bacterial polysaccharide produced by fermenting a specific microorganism (Sphingomonas elodea). It was discovered in the 1970s and has since become a go-to gelling agent in food science and, increasingly, in cosmetics. It forms beautiful, optically clear gels at very low concentrations — far less than agar or carrageenan.

Like carrageenan, gellan gum comes in two distinct forms that behave very differently. High-acyl gellan (also called native or natural gellan) makes soft, elastic, thermoreversible gels — the kind you’d describe as “bouncy” or “jiggly.” Low-acyl gellan (also called clarified or deacylated) makes firm, brittle, crystal-clear gels that fracture cleanly and are not thermoreversible at typical use levels. The clarity of low-acyl gellan gels is remarkable — they look like glass.

For DIY cosmetics, gellan gum is the modern alternative to agar agar and carrageenan when you want precision, clarity, and efficiency. Its low usage rate (0.2-1%) means a little goes a very long way.

What it does in a formula

Gellan gum’s primary role is gel formation, but the gel type depends entirely on which form you use:

• High-acyl gellan: Produces soft, elastic gels that melt in the mouth (food) or spread smoothly on skin. Sets on cooling (around 70 C pour, sets at 50 C). Thermoreversible — reheats to liquid. Ideal for serum gels, sleeping masks, and “water-drop” textures.
• Low-acyl gellan: Produces firm, brittle, water-clear gels that set at room temperature when ions are present. Not easily re-melted. Perfect for clear gel products, fluid gels (sheared during cooling for a pourable gel texture), and suspension gels that hold particles.

Both forms also work as suspending agents at sub-gelling concentrations — keeping beads, shimmer, or botanical extracts evenly distributed in liquid products.

How to use

• High-acyl gellan: Disperse in room-temperature water, then heat to 85-90 C with stirring until fully dissolved. Pour at 70 C into moulds or jars. Gel sets around 45-50 C. Use 0.3-0.8%.
• Low-acyl gellan: Disperse in deionized water, heat to 75-85 C until dissolved. Add ions (a pinch of calcium chloride or magnesium sulfate, 0.05-0.1%) to trigger gelation on cooling. Sets around 30-40 C. Use 0.2-0.5%.
• Fluid gel technique (low-acyl): Heat, dissolve, then shear vigorously (immersion blender) while cooling through the setting point. The result is a smooth, pourable gel with a yielding texture — excellent for serums.
• Suspension (either type): Use 0.1-0.3% to keep particles suspended in toners or micellar waters without forming a rigid gel.

Best for / Worst for

Best for: clear gel serums, sleeping masks, fluid-gel textures, suspension of particles in toners, water-drop creams, hydrating gel masks, modern “bouncy” skin-feel products.

Worst for: anhydrous products, very acidic formulas (below pH 4), products where you want a heavy/rich texture, formulas with very high electrolyte content (over-gels or crashes out).

Common pitfalls

Using tap water with low-acyl. Low-acyl gellan is extremely sensitive to ions. Tap water contains enough calcium and magnesium to trigger premature gelation during heating, creating lumps. Always use deionized or distilled water.

Confusing high-acyl and low-acyl. They behave completely differently. High-acyl = soft/elastic/hot-pour. Low-acyl = firm/brittle/sets at room temp. Swapping one for the other in a recipe will fail.

Too much concentration. Gellan is potent. At 1%+ with ions, low-acyl gellan makes a gel so firm it cracks. Start low (0.2%) and increase in 0.1% increments.

Not accounting for ion sensitivity. Adding electrolyte-rich ingredients (sodium lactate, mineral extracts, magnesium-rich waters) to a low-acyl gellan formula will strengthen or break the gel unpredictably. Add those ingredients before the gellan, and adjust gellan concentration accordingly.

Expecting high-acyl to set at room temperature. High-acyl gellan needs hot preparation and sets on cooling. It won’t thicken a cold formula the way xanthan or carbomer would.

Substitutes

• Agar agar — similar heat-set gel, firmer and more opaque, much higher usage rate.
• Carrageenan (iota) — soft elastic gel, but less clear and requires higher concentration.
• Xanthan gum — thickener only, no true gel, but much easier to use cold.
• Sodium alginate — cold-process gel with calcium, different mechanism entirely.
• Carbomer — clear gel at room temperature, but acidic and needs neutralization.